Are lockable power switches required for industrial equipmemt that can be unplugged?

For one-off/custom built pieces of manufacturing equipment that can be simply unplugged before servicing, is it still necessary to have a lockable power switch? My local AHJ says that as long as the switch is within sight of where the servicing is being done then it's OK to not have a lockable switch. However much of the equipment gets shipped to third party contract manufacturers in other states and Canada. So I'm want to be compliant with the code even if my local AHJ doesn't care to have a copy of NFPA 79 or 70b. Furthermore, I'm curious why none of my local Electrical Engineering firms or regional electrical contractor firms that I'm aware of have those codes, and none of my half dozen+ contact manufactures have required labeling of the short circuit current rating on the equipment name plate. Is compliance with NFPA 79 and 70B just very uncommon, or am I missing something?